Rotary underreamer



Sept. 23, 1930;

5. M. AKEYSON ROTARY UNDEEREAMER 2 Sheets-Sheet 2 Filed flov. 12, 1927 l TTOR/VEK Patented Sept. 23, 1930 r ,SW-AN M..AKEYSO1\T, OF LQNG BEACH, CALIFORNIA ROTARY UNDERREAMEB lp plication filed novenber z, isv. Serial No. 252,883.

An object of myinvention is to provide a novel rotary underreamer in' which anew cutting edge is constantly presented tothe surface to be cut.

Another objectis to provide an underreamer in which the various superimposed cutters are all expanded'or retracted'by the actionof one or more of 'thecutters. p

A furtherobject is to provide an underreamer which is positively closed as it moves upwardly into the casing. Q L

Astill further object is to provide an underreamer in which dirt,sand, and the like are eifectively prevented frmn'gettingintO the moving parts thereof.

Other objects, advantages and features of invention may appear in the accompanying drawings,'the subjoined-deta-ileddescriptions,

and the appended claims! In the drawing' I lgure 1, is aside elevation of my reamer.

Figure 2, is a longitudinal sectional view ofthe same. I

Figure 3,is-a sectional'viewtaken on line 33 otFigure 2.

Figure/his a side elevation of the inner cuttersleeve. l l

Figure 5, is a side elevation, partly in sec tion, of theinner sleeve.

Figure 6, is a plan view of the same.

Figure 7, is a side elevation, partly in section, of the bearing ring.

F igure '8,-is a plan view of the same.

Figure 9, is aplan view of a modified form of sleeve. Q 5 I Figure 10, is a side elevation of the same.

Referring more particularly to the drawing, my underreamer comprises a headl to which the drill pipe is secured, by a suitable means such as a threaded boa or-pin, atubular mandrel 2, is secured to and depends from the head lI It is obvious thatthe mandrel maybe integralwiththe head or may be threaded therein as desired. A plurality of superimposed cutter elements3, are mounted on the mandrel 2, and these elements being identical in construction only one will be discussed in detail.

A sleeve 4, is eccentrically mounted on the mandrel 2, and is keyed thereto by a key 5, which extends longitudinally of the 'mandrel and the various sleeves, being provided "Witha slot into which the key enters.

The stationary sleeves are positioned at dif ferent angles to eachfother so "that'the cut ting surfaces will be engaging the hole at variouspoints throughout the 360degrees of arc. lhis ismore clearly brought out *through examination of Figure 3.,

A ring6, isrotatably mounted upon the sleeve 4, and eccentrically positionedfon the sleeve, and the ring is so arranged as to only partially rotate on, the sleeve.

A flange 7 is formed on the top of thesleeve l, against which the ring 6, rests, thus limiting the upward movement'of the ring. The sleeved, is provided with vertically extending key 8, which engages a shoulder 9, in the ring 6, thus limiting the rotary movement of the ring.

A plurality of horizontally extending and arcuate lugs 10, are, formed in the sleeve 4,

and terminate in the key 8. "These lugs are adapted to enter arcuate ways 11, in the ring 6, when the ring is in the extended or cut-' ting position, thus preventing longitudinal.

movement of the ring along the mandrel and add great strength and rigidity to the cutters. In order to remove the 'ringfrom the sleeve a cut 12, is provided in the ring of sufficient width to accommodate the lugs 10, so that when the lugsare moved into the cut the ring may be slipped downwardly oft of the sleeve. Y

A cutter ring 13, is journaled on the ring '6, and rotates during the cutting operation of the tool. I The exterior surface of the cut ring is provided with suitable: cutting teeth to'suit the particular needs of the formation in which the reamer is operated. i p

A flange 14, at the top of the ring 6, limits the upward movement of the cutter ring. A plate 15, rests against the bottom of the ring 6, and projects beyond the edge thereof, thus providing a bottom bearing for the cutter ring 13, and serves to hold the last named mug in operative position. The plate 15, is held in position on the tool by the flange 7, of the next adjacent cutter, the lowermost plate being held by a collar 16, which is held in place'by a locked nut 17, and a nut 18. The nuts 17, 18, screw onto the bottom of the mandrel 2, and serve to hold the cutters in position on the mandrel. j

If desired, a packing ring 19, may be provided on the inner surface of the ring 6, to prevent foreign matter from entering the journals of the cutters.

In removing the tool from the well, if the cutters will not of themselves move into retracted position when-the drill pipe is reversed in rotation, I provide a spiral cam 20, which extends upwardly from the uppermost ring 6, and engages the bottom edge of the casing, to rotate the uppermost cutter into retracted position. Each successive lower cutter is then moved into a retracted position by coacting lugs 21, 22, on the lower and upring 6 is provided with extending cutter teeth 23, on the high side thereof, so that a cutting action is had during the rotation of the tool.

As previously stated, the mandrel 2, is hollow, and the nut 18 is provided with a bore 2 1, through which the drill mudpasses to provide circulation in the hole. Any other desirable means may be provided for the circulation of the drilling mud, and ports may be provided at various emission of the mud.

Having described my invention, I claim:

1. A rotary underreamer comprising a mandrel, a plurality of superimposed cutter elements on. said mandrel, and a cutter ring rotatably mounted on each of said cutter elements, and coacting means on each of the adjacent cutter elements whereby said cutter elements are all extended or retracted together.

2. A rotary underreamer comprising a head,a mandrel depending from the head, a plurality of cutters on said mandrel, each of said cutters comprising a ring, partially rotatable on the mandrel and a cutter ring rotatably mounted on said first named ring, means on the upper cutter adapted to be engaged by the casing when the reamer is removed from the hole whereby said cutter is moved to a retracted position, and means points for the on adjacent cutters adapted to coact and move said cutters to retracted position.

3. A rotary underreamer comprising a head, a mandrel depending from the head, a sleeve keyed to the mandrel, said sleeve eccentrically mounted on the mandrel, a ring partially rotatable on the sleeve and eccentrically mounted thereon, and a cutter ring rotatably mounted on said first named ring, means on the upper cutter adapted to be engaged by the casing when the reamer is removed from the hole whereby, said cutter is moved to a retracted position, and means on the adjacent cutters adapted to coact and move said outters to retracted position.

4. A rotary underreamer comprising a head, a mandrel depending from the said head,a sleeve keyed to the mandrel and eccentrically mounted thereon, a ring eccentrically mounted on the sleeve and partially rotatable thereon, a vertical key on the sleeve, and a shoulder on the ring adapted to be engaged by the keyto limit the rotation of the ring, horizontal lugs on the sleeve, said ring'having slots therein to receive the lugs when the ring is in extended position.

5. A rotary underreamer comprising a head, a mandrel depending from the head, a plurality of superimposed cutter units on the mandrel, each cutter unit comprising a sleeve keyed to the mandrel and eccentrically mounted thereon, a ring, eccentrically mountved on the sleeveand partially rotatable thereon, a key in the sleeve, a shoulder on the ring whereby rotation of the ring 1s limited, lugs on the sleeve, said ring having slots to receivethe lugs when the ring is in extended position, said ring having a cut thereon to accommodate the lugs when in the retracted position, whereby the ring may be removed from the sleeve and a cutter ring rotatably mounted on said first named ring.

6. A rotary underreamer comprising a head, a mandrel depending from the sald head, a sleeve keyed to the mandrel and eccentrically mounted thereon, a ring eccentrically mounted on the sleeve and partially rotatable thereon, a vertical key 011 the sleeve, and a shoulder on the ring adapted to be engaged by the key to limit the rotation of the ring, means on the upper cutter adapted to be engaged by the casing, when the reamer is removed from the hole whereby said cutter is moved to a retracted position, and means on adjacent cutters adapted to coact and move said cutters to retracted position.

7. A rotary underreamer comprising a head, a mandrel depending from the said head, a sleeve keyed to the mandrel and eccentrically mounted thereon, a ring eccentrically mounted on the sleeve and partially rotatable thereon, a vertical key on the sleeve, anda shoulder on the ring adapted to be engaged by the key to limit the rotation of the ring, means on the upper cutter adapted to be engaged by the casing, when the reamer is removed from the hole whereby said cut ter is moved to a retracted position, and means on adjacent cutters adapted to coact and move said cutters to a retracted position, said means comprising a spiral cam secured to the uppermost ring, and lugs extending from the adjacent ring adapted to engage the simultaneous moving of the rings.

In testimony whereof I afl'ix my signature.

SWAN M. AKEYSON. 

